Moscow Polytechnic University (Moscow, Russia):

Yu. G. Kalpin, Dr. Eng., Prof., Dept. of Metal Forming and Additive Technologies, E-mail: kalpin@inbox.ru
Yu. K. Filippov, Dr. Eng., Prof., Dept. of Metal Forming and Additive Technologies, E-mail: yulianf@mail.ru
S. A. Egorov, Post-graduate
V. I. Mishin, Post-graduate

A sample is tested for material testing for plastic uniaxial compression. Based on a brief analysis of the deformation process of a traditional cylindrical sample, its main drawbacks are described. A sample is being simulated to test materials for plastic uniaxial compression with different head geometries. Q-Form 3D finite element system is used for modeling. The initial data and simulation results are given. When analyzing the results of the study, recommendations have been developed that show that it is advisable to make the compression sample variable across the section height. The largest diameter should be done end surfaces, and the smallest diameter of the sample should be in the middle. The transition from the end surface should be gradual and this decline in its form approaches the cone with an angle of about 30°. Based on the simulation, the shape of the sample for testing materials for plastic uniaxial compression was developed and substantiated. In the course of experimental studies on samples made in accordance with the proposed recommendations, a hardening curve was constructed for large values of the true deformation (more than 2.5) with the standard test using the draft method. A more accurate hardening curve was constructed (with a minimum error of less than 2%) as a result of precipitation of a corset sample from a metal with less complexity of the testing process. The results of the discrepancy between the hardening curves are shown and the theoretical aspects related to the advantages of using new-shaped samples are described.

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